Arvid Schneider is an awesome guy that creates extremely high quality tutorials. Check out his website and Youtube Channel. He made a great tutorial on how to create Captain America’s shield, teaching a thing or two about anisotropy.
He covers a lot of topics in a very short time. I had some difficulties to follow a couple of his steps. So here is a rewrite of the tutorial with my personal preferred way of doing things. However definatly go check out the video, he describes the steps in much greater detail.
Part 1: Modeling the shield
I am going to be using a Poly Sphere to create the shield.
Create a Poly Sphere. In faces mode select the lower part of the ball.
(If you selected a little more than the half re-position the Pivot Point)
Scale the half-sphere down.
RotateZ = 90
Create a UV-Layout. The important thing is, since in the tutorial a lot of ramps with the circular attribute are going to be used that the center of the UVs are placed exactly in the middle.
The easiest way to get a perfect placement is to use “UV > Planar”, and Project from the X-Axis.
Part 2: Initial Render Setup
Step 1: Camera
Create a Render_Cam (**Create > Camera > Camera**)
**Panels > Look through Selected**
**View > Camera Settings > Resolution Gate**
Position the Camera
Initially I set up the camera just like in the tutorial with the shield slightly slanted. This setup has the benefit that you can clearly see the reflections.
For the final image I chose to re-position the camera for a more frontal view of the shield.
Step 2: Lighting
Arvid Schneider does not go into his lighting Setup, in essence he has a “Studio Lighting” and a “Outdoor Lighting” HDR setup.
I only used a basic Studio Lighting with the help of two Area Lights, (Exposure 12, and Exposure 17)
Part 3: The Shader
Arvid Schneider recommends to connect the newly created ramp into the diffuse color attribute, so you can immediately see the color output
Step 1: alShader
Create a new alShader “al_shield” and assign it to the shield.
Step 2: Base Colors + Star
In the Hypershade editor press Tab and create a new “ramp (texture)” (base_color), connect it directly to the diffuse color of the alShader.
Change the Type to “Circular Ramp” and the Interpolation to “None”
In the Attribute Editor adjust the colors of the gradient:
Use a reference image of the shield, and the Arnold Renderview to determine how wide the various segments of the gradient need to be.
To add the star, first google for a star image. (The star should be white, if not you should edit it in Photoshop)
In the Hypershade create a “aiCombineColor” Node, Change the Combine Op to add 1+2.
Connect the ramp “base_color” to input1 and “out color” to “al_shield” Diffuse Color.
Create an aiImage Node, import the star and connect it to input 2.
Change Wrap U and Wrap V to file, to ensure that you only have a single star.
With Scale U and Scale V, you can make the star bigger or smaller (larger numbers make the star smaller, smaller numbers makes the star bigger)
Finally position the star using the Offset U and Offset V Attributes.
If everything is looking good, break the connection to the “diffuse color” and connect the aiCombineColor1 to the Specular 2 Edge Tint and to the Specular Color 2 Reflectivity.
Set the Strength of Reflectivity 2 to 1 and the Fresnel Mode to metallic.
Step 3: Ansiotropic Map
The Ansiotropic Map is going to be used as a bumpmap, and should simulate the small ridges in the surface.
In the Hypershade create a “ramp (Texture)”, name it ramp1. (Make it Type Circular)
Open the Script Editor (python) and use following code to create a ramp with many many small ridges.
If you want to show off your awesome modelling skills, there is no better way then to show off the models wireframe. You could do a quick screenshot of your model in wireframe mode, but that looks cheap and not very impressive. It would be better to render the object using a render engine.
I will show you how you can make a clean, technical and awesome looking image using mental rays “contour” render option. To use this feature you have to activate it in the render settings and then apply a shader to the object. This way you can set up an environment that is rendered normally and your hero object is rendered as wireframe object.
You probably neither have seen or heard of this feature due to that this feature is only found in the “legacy mode” of Mental Ray and even then it is still hidden in the advanced settings.
Set “Render Using” to “mental ray”
Open the “Quality”-tab
Enable “Show Advanced Settings“
Expand “Legacy Options“> Set Sampling Mode to “Legacy Sampling Mode”
Expand the “Draw by Property Difference”-section > Enable “Around all Poly Faces”
First create a white Lambert material “mat_wireframe”
Navigate to the Shading Group “lambert2SG”, and rename it to“mat_wireframeSG”
Expand the mental ray section, and the subsection “Contours”
Enable “Contour rendering”, and set the color to black.
Apply the material to a test object (like a poly sphere) and do a render.
If necessary adjust the value of the width (0.5 usually has nice results)
Now apply the material to the objects that you would like to render as wireframe.
Note: if you render objects with “smooth mesh preview” enabled (By pressing the Key 3), mental ray renders a more complex wireframe. In such cases selecting the object and pressing the key 1 enables mental ray to render out the low poly version.
The IES (Illumination Engineering Society) standard format file stores information about the distribution of light from a real light source. Profiles are created by measuring light bulbs in the real world.
Now that sounds quite boring, wouldn’t the light profiles be exactly the same as a normal CG light? Well, it really depends on the physical attributes of the lightbulb. For example many halogen lightbulbs have small reflectors in them causing the light to have very characteristic hotsposts.
We are going to take a look at how to use these profiles with Mental Ray and Arnold.
Where to get IES Files?
Most of these profiles are available for free on the light manufacturers websites.
We will be taking a look at how you can light your scene using the “infinite white background” look. This look is commonly used to present technical stuff or single objects.
In my example I am going to use a model of a dragon statue. First we will be taking a look at how to achieve the effect using only Final Gathering and after that we will take a look at using ambient occlusion as a light source.
Create a Poly Plane with a white lambert and import your object.
Create a Camera. Set the Environment> Background Color to White
For the Final Gather technique we will not use any lights. The default light would only cause unwanted side effects.
To disable the “default light”, open the Render Settings in the “Common” tab open the panel “Render Options” and remove the check at “Enable Default light”.
The Final Gather Effect will use the environment color of the camera to light the scene. You only need to activate Final Gather and you will see the result.
Ambient Occlusion Light Source
Create an Area Light. In the Attribute Editor under mental ray > Area light, activate Use Light Shape.
Connect to the Attribute “Custom Shaders > “Light Shader” a “mib_amb_occlusion” node.
Step 3 (optional)
To increase the render quality you can adjust the attributes “Samples” and “Max Distance“.
This time let’s render our awesome neon sign using SolidAngle: Arnold. For this we will reuse the model from my previous article Mental Ray: Create a Retro Neon Sign and just swap the shaders for Arnold shaders.
Create and assign a aiStandard material and set following Values
Create and assign a aiStandard material and set following Values
The shader setup is simpler than in mental ray and the render speed is faster 7min mental ray vs arnold 3min.
Today we will be creating a cool looking neon sign. Neon signs were extremely popular in the US from 1920-1960. These days you will still find many stores use neon “open”- signs and especially a lot of “Las Vegas”-signs are neon lights.
The way a neon sign works is that a custom shaped glass tube is filled with gas. Then when the gas is electrified it starts to glow. To create different colors you simply have to tint the glass with the color you want.
To create realistic neon light in Maya we are only allowed to model glass tubes and we need create two things, a representation of the gas and the glass tube.
First we will model the light using “Bezier-Curves” and “Poly-Extrude”. To render the light we will be taking a look at the mental ray “mia-light-surface” Texture and “object-light” Shader.
Create your sign using the “Bezier Curve Tool”. For each letter create a new curve. Consider the limitations of glass tubes. Some letters, like “E”, cannot be completed in a single stroke, for these use multiple tubes / curves are required. Other letters like “O” cannot be perfectly round since the glass tube needs to go back to the electrodes. (Of course skip duplicate letters)
Create a Poly Cylinder (Subdivision Axis 8) and set the radius to whatever thickness you need your light to be. Duplicate it for each curve you have and position it at the beginning of the curves.
Select the top faces and the curve and Extrude (Ctrl-E). In most cases you will need to add divisions so the geometry looks correct. (In some cases you will need to manual adjust the vertex points to get a good result)
Select all geometry and select Mesh > Combine.
Select all faces and Extrude (Ctrl-E) with a thickness of 0.2.
Without deselecting the faces Edit Mesh > Duplicate Faces. This is our “gas”-geometry.
Create and assign a “mia_material_x” material. From the Presets select “Glass_Physical”
In the Attribute Editor go to “Advanced” and connect a “mia_light_surface“.
Set the values to:
Color: Red (or whatever you need)
Fg Contrib: 1.0 (or higher Values like 5.0, increases the glow distance)
Refl Contrib: Same as Fg Contrib
Create and assign to the “gas” component a mental ray “object_light” shader. Set the intensity to 1000.
If you do not have an environment you will not see the glow effect. For my simple render I just used a simple Poly Plane with a black lambert as the environment.
Set up your Render_Cam.
In the Render Settings, Quality-Tab enable Final Gather.
The mia_material_x has an artificial specular highlight, seemingly reflecting the light source, even though no light source is “visible”. This can cause unwanted effects especially when using multiple lights.
The specular highlight can be controlled in the shader attributes go to Advanced > Specular Balance. To disable it the value to 0.
In the example image on the left you can clearly see a reflection of the key, fill and even rim light. On the right I set the “Specular Balance” to 0.
Image Based Lighting (IBL) allows you to use High-Dynamic-Range (HDR) images as. To efficiently use sIBL images you would need to set up an entire Shading Network.
Smart IBL (sIBL) is a open system that allows a quick and easy IBL setup in 3D Applications. It especially takes care of the issue Of color noise gets created in the rendered animation caused by Final Gather. sIBL uses blurred images in combination with the original Image use in the reflections.
To work with sIBL Images you need two Parts
sIBL-GUI is a Gallery Viewer that can send Images
A plugin that allows your 3D Application to receive the image from sIBL-GUI
Open sIBL, Add the “Tropical Beach” to the Libary (In Library Mode right click in the middle panel and select “Add sIBL set …” )
Select the “Export” panel
In the left panel select “Mental Ray Standard” (Creates an environment)
In the middle panel select the Image, in the right panel click Output Loader script
Back in Maya go to the sIBL shelf and click on the E (execute)
In the Outliner you see a group “sIBL” has been created. It includes a transparent floor to receive shadows.
In the Hypershade you can Graph the persp-Camera here you see the entire IBL-network that has been created. If you create a new Camera you have to connect the sIBL_mip_rayswitch to the mental ray > Environment Shader Attribute
In the Viewport activate Shaded and Textured mode (Press the key 6)
Position your Render Camera
Apply a “mia_material_x” shader to the teapot (A white tone)
Test render (make sure Final Gather is activated)
If the image is too bright, check the Gamma Settings on the “sIBL_mia_exposure_simple” and set it to 1.0
Adjust Final Gather settings and Anti-Alias Settings for Final Render (increase Accuracy, Point Density) and then do your final Render.